In recent years, image forming apparatuses such as a multifunction printer (MFP) including functions of a printer, a copying machine, FAX, and the like have been in widespread use. The image forming apparatuses generally include almost all functions necessary to complete office work, are compact, do not take up too much space, and are also excellent in terms of costs. Thus, the widespread use of these image forming apparatuses is expected to increase.
Additionally, some image forming apparatuses include the double-sided printing function which forms an image on one side of a printing sheet and thereafter forms an image on the reverse side of the printing sheet (for example, refer to Japanese Patent Application Laid-Open No. 2006-126251). In the double-sided printing, an image is also formed on the reverse side by forming an image on one side of the printing sheet in an image forming section and then feeding and reversing the sheet through a double-sided sheet passing path to feed the sheet again into the image forming section.